Exam 16: Microbial Life: Prokaryotes and Protists

Which two groups of protists produce hard, mineralized skeletal structures or cell walls that contribute to marine sediments and form fossils?

________ are stramenopiles that commonly are found decomposing dead animals in freshwater habitats.

Which organisms are common soil decomposers that grow in colonies of branched chains of cells that superficially resemble a fungus?

In the 1930s, the Navajo Nation treated sheep and cattle for ticks and other parasites by using concrete "dip tanks," a common practice in the United States during that time period. Animals were herded into one end of the tank and out the other. Each day, the tanks were filled with 200,000 gallons of insecticide, and any remaining chemicals were emptied onto the ground. The pesticide solution seeped into the ground, ditches, and pits around the tanks. In the 1990s, the EPA Emergency Response Team (ERT) was called to the Navajo Nation to investigate the problem. They concluded that bioremediation procedures were the best option for cleaning up the site. Certain types of bacteria are able to feed on and digest toxic organic substances, such as pesticides, and use them as fuel for cell respiration. The ERT distributed these pesticide-eating microorganisms throughout the contaminated soil to remove the chemical residues. Once the contaminants are degraded, these microorganism populations will die off because they will have used up all of their food supply. -The bacteria used in this bioremediation procedure are

Barry Marshall and his collaborators showed that

In 2012, scientists studied modern Marchantia liverwort plants and observed that they not only are able to make their own food using energy from sunlight but they also absorb carbon from plant material in aquatic environments. They classified this plant as a

Bioventing is a scientific technology that uses microorganisms to break down components of fuels in groundwater. Bioventing is an example of

Unlike archaean and eukaryote cell walls, bacterial cell walls contain a unique substance called

-Which of the following contains only protist clades?

-Which group has the least scientific support for its position in the phylogeny?

A scientist cultures the dried soup from a 4,000-year-old cooking pot found in an Egyptian tomb and obtains a distinctive species of prokaryote. She immerses a test tube of these bacteria in boiling water for several hours, but the colony grows back. This species is probably

In a process called phytoremediation, specific plants are planted in areas where toxic chemicals have contaminated groundwater. The roots absorb the contaminants to help eliminate the tainted water, which is often drinking water. This is an example of

Which of the following options correctly pairs a structure in prokaryote cells with its function?

Evidence for similarities between Archaea and Eukarya includes the

A negative impact of biofilms in the human body is that biofilms can cause head and neck diseases. A study was completed that compared three groups of medical patients for presence or absence of biofilms. Group 1 were patients with chronic otitis media (COM), a disease where the eardrum continually drains and can often become clogged, that also displayed ear discharge. Group 2 were COM patients without ear discharge. Group 3 were patients undergoing surgery for cochlear implantation, a procedure where a small electronic instrument is placed in the ear to carry out normal functions of the inner ear. Two microscopy methods were used to detect presence of biofilms in all patients of both groups: direct microscopy (DM) and transmission electron microscopy (TEM). The table below shows the results of presence or absence of biofilms in all study participants. Table 1. Number of study participants detected with biofilms Group Group Size Biofilm on DM Biofilm on TEM 1 COM, discharge 10 10 10 2 COM no discharge 9 2 2 3 B cochlear implant 10 0 0 Total 29 12 12 Source: Adapted from Akyıldız, I., Take, G., Uygur, K., Kızıl, Y., & Aydil, U. (2013). Bacterial biofilm formation in the middle-ear mucosa of chronic otitis media patients. Indian J Otolaryngol Head Neck Surg, 557-561. doi:10.1007/s12070-012-0513-x -How can you interpret results of the study?

Diatoms

Eukaryotes are ________ prokaryotes.

The trickling filter at a sewage treatment plant works by

One difference between gram-positive and gram-negative bacteria is that

________ are heterotrophic protists; ________ are photoautotrophic protists.